Cefaclor or 3-chloro-7-D-(phenylglycinamide)-3-cephem-4-carboxylic acid is a semi-synthetic cephalosporinic antibiotic described for example in U.S. Pat. No. 3,925,372 and German Patent No. DE 2,408,698 (Eli Lilly & Co.). Its bactericide action is based on its capacity to inhibit cell wall synthesis. Cefaclor is indicated for treatment of infections caused by sensitive strains of numerous organisms, particularly Streptococcus and Staphylococcus.
Pharmaceutical forms currently available for administration of cefaclor include capsules, retard tablets and suspensions, both in phial and sachet form.
There are a number of limitations and drawbacks to the use of capsules affecting the following:
their administration to the patient, which may be limited because some may have problems in swallowing them, particularly children and the elderly who may even be unable to do so; and PA1 the fact that they permit only a single dosage. PA1 risk of accidental overdose due to uncontrolled consumption, particularly in children; and PA1 the difficulties of handling and transport because of the volume involved, leading to some risk of failure to complete the therapy, with the attendant loss of efficacy. PA1 i) Their high rate of disintegration in water, and PA1 ii) The uniform distribution of the particles into which they disintegrate. PA1 They are suitable for treating patients with difficulties in ingesting solid forms; PA1 They may be used by diabetic patients since they do not contain saccharose; PA1 Dosage is flexible and reasonably accurate following dissolution in the volume of water desired by the patient. PA1 The resulting solutions are of suitable organoleptic characteristics, acceptable to patients. PA1 Their shape, size and reduced volume allow them to be presented in blister form, which is a benefit to the patient, enhancing ease of handling and carrying, to ensure that the patient completes the therapy, thereby raising the efficacy of treatment; and PA1 There is less risk of accidental intoxication due to overdose, making them less hazardous, particularly to children.
On the other hand, the drawback to cefaclor administration in suspension (sachets) is that, due to its saccharose content, its potential use is limited in diabetic patients, who must take the appropriate precautions.
Moreover, added to this drawback caused by the saccharose content, administration of cefaclor in suspension (phial) has further disadvantages which may be summarised as follows:
Retard tablets have the drawback of not permitting double dosage of the product; moreover, they are not suitable for patients with difficulties in ingesting solid forms.
Existing forms of administration of cefaclor do not in general meet entirely satisfactorily some requirements considered desirable in the treatment of bacterial infections, for example their application to any patient in conditions such as to ensure that the therapy is completed, thereby enhancing its efficacy.
There is thus a requirement for new pharmaceutical forms for administering cefaclor which solve these problems, making it easier for the patient to administer them, and so that they can be used with diabetic patients without causing additional difficulties, so increasing the efficacy of treatment. This invention provides a solution to these problems, by furnishing new pharmaceutical formulations containing cefaclor which are suitable for the manufacture of dispersible tablets.
Dispersible tablets are solid pharmaceutical forms for oral administration which must disintegrate in less than three minutes in water at 19.degree. C.-21.degree. C. and disperse evenly in the water. The dispersion uniformity trial involves placing two tablets in 100 ml of water and shaking them until they are completely disintegrated; they must disperse so as to pass through a screen with a nominal mesh size of 710 microns (Brtitish Pharmacopea Vol. II, 1988).
Dispersible tablets are known which contain antibiotics belonging to the synthetic penicillins group (amoxycillin) and anti-inflammatories (pyroxycam), but none is known which contains an antibiotic belonging to the synthetic cephalosporin group, such as cefaclor.
The subject of this invention is new pharmaceutical formulations containing cefaclor suitable for the manufacture of dispersible tablets. A further subject of this invention consists of such dispersible tablets containing cefaclor, and their manufacturing process.